Re-isolation of Ektaphelenchus winteri (Hooper, 1995) Heydari & Pedram, 2020 (Rhabditida: Aphelenchoididae) from Xylodiplosis nigritarsis (Diptera: Cecidomyiidae) in Norway

Summary Ektaphelenchus winteri was re-isolated from the county of Færder, southern Norway. Nematodes were feeding on larvae and adults of the gall midge Xylodiplosis nigritarsis as ectoparasites, i.e. , the nematode spears the host’s cuticle and sucks its blood using the stylet. Nematode specimens were collected and morphologically and molecularly examined, although only female materials were available. Generally, the typology of the re-isolated population corresponded well with the type population, with some minor differences. Molecular phylogenetic analysis suggested that E. winteri is closely related to Ektaphelenchoides fuchsi and ‘ Seinura demani ’, but was readily distinguished from these two species by its stylet lacking clear basal swellings, anteriorly located secretory-excretory pore, spherical-oval median bulb, and female elongate conoid posterior body. A literature review confirmed typological similarity between S. demani and E. fuchsi , as well as the vestigial rectum and anus in S. demani . Based on these characteristics, Ektaphelenchoides demani n. comb. is proposed.